The present invention relates to a slitter-winder of a fiber web production line in general, and in particular to guards for increased safety of a slitter-winder and severing of the fiber web in the slitter winder.
It is known that a fiber web, e.g. paper, is manufactured in machines which together constitute a paper-manufacturing line which can be hundreds of meters long. Modern paper machines can produce over 450,000 tons of paper per year. The speed of the paper machine can exceed 2,000 m/min and the width of the fiber web can be more than 11 meters.
In paper-manufacturing lines, the manufacture of paper takes place as a continuous process. A fiber web completing in the paper machine is reeled by a reel-up around a reeling shaft, i.e. a reel spool, into a parent roll, the diameter of which can be more than 5 meters and the weight more than 160 tons. The purpose of reeling is to modify the fiber web manufactured as planar to a more easily processable form. On the reel-up located in the main machine line, the continuous process of the paper machine breaks for the first time, and shifts into periodic operation.
The web of the parent roll produced in paper manufacture is full-width and can be more than 100 km long so it must be slit into partial webs with suitable width and length for the customers of the paper mill and wound around cores into so-called customer rolls before delivering them from the paper mill. This slitting and winding up of the web takes place as known in an appropriate separate machine, i.e., a slitter-winder.
On the slitter-winder, the parent roll is unwound, the wide web is slit on the slitting section into several narrower partial webs which are wound up on the winding section around winding cores, such as spools, into customer rolls. When the customer rolls are completed, the slitter-winder is stopped and the wound rolls, i.e., the so-called set, is removed from the machine. Then, the process is continued with the winding of a new set. These steps of so-called set change are repeated in sequences periodically until paper runs out of the parent roll, whereby a parent roll change is performed and the operation starts again as the unwinding of a new parent roll.
Slitter-winders employ winding devices of different types depending on, inter alia, the type of the fiber web being wound. On slitter-winders of the two drum winder type, the web is guided from the unwinding via guide rolls to the slitting section where the web is slit into partial webs which are further guided to the winding (support or carrier) drum of the two drum winder, and slit component webs are wound around a winding core supported on two drums or one drum or a set of drums or two sets of drums. The present invention relates to two-drum winders with two winding drums.
On many two drum winders, space beneath the winding drums is limited, making maintenance and paper broke (scrap) cleanup difficult. In some cases the limited space is also a safety concern.
In two drum winders various web cutting blade arrangements have been used to sever the web from a completed wound roll during the set change sequence so it can be started onto a new set of cores, and to sever the web during the threading process. The most prevalent method has been a blade mounted from a support beam with the blade coming up between the front and rear winding drums, which requires various linkage and cam roller guides to guide the cross-machine support beam and considerable space is required under the winding drums.
During recent years a splice guard (a guard) has been used on some winders to cover the top of the rotating front (downstream) winding drum to protect operators from contact or entry into the nip produced by the front drum and a partially wound roll when threading the winder to a partially wound roll after a web break. The movable winder guard is typically pivoted about the axis of the front winding drum.
The cutting operation has been provided either with a cutting blade moving vertically in the space between the winding drums or with a cutting blade moving in an arcuate path around the rear (upstream) winding drums. On many winders, space beneath the winding drums is limited making maintenance and paper broke (scrap) cleanup difficult. In some cases the limited space is also a safety concern. Thus providing also the safety guard with the front winding drum has been problematic as the construction space needed raises further problems in this limited space beneath the winding drums.
In U.S. Pat. No. 4,368,855 is disclosed a known web winding apparatus comprising a pair of space apart support rolls (winding drums) for a core tube (winding core) to be placed thereon, means for driving at least one of said rolls, means for delivering a web onto a core tube supported on said rolls, and means for cutting (severing) the web when it is desired to replace the core tube, wherein said cutting means comprises an elongated blade extending longitudinally of the rolls, and means for advancing and retracting said blade in the space between said rolls so as to contact and cut said web in advanced position and to withdraw said web into standby position between cuttings. The blade can be caused to move in a straight line or an arcuate path between active and inactive positions and guide means may be provided to prevent skewing. It is disclosed that in this known arrangement the cutting means move in the straight line in a vertical direction between the support rolls or in the arcuate path around the rear, i.e. the upstream support roll.
In U.S. Pat. No. 6,616,085 is disclosed a winding splicing nip guard, which is mounted for rotation about the downstream drum of a winder having two spaced apart winding drums which support a customer roll. The guard has a D-shaped leading-edge which approaches the customer roll. The leading-edge is articulated so that if an operator hand becomes wedged between the leading-edge and the customer roll, articulation on the leading-edge closes a switch which brings the winder to a stop. A hydraulic actuator extends between a lowermost radial edge of each sector shaped extension and a fixed support. Operation of the hydraulic actuator causes the guard to rotate about the axis of the downstream winding drum so as to be between the operator and the downstream side of the winding drum. The leading edge of the guard is positioned to limit operator access to the nip formed between the customer roll and the downstream winding drum.
U.S. Pat. No. 6,588,698 discloses a winding machine comprising a winder drum, and a roll core at least partially supported on the winder drum, and a web of material being wound around the roll core to form a web reel in response to rotation of the winder drum and the web reel, the point where the web reel rotates into contact with the support drum being called the nip. The winding machine further includes a nip safety guard having a finger presence sensor, the nip safety guard supporting the finger presence sensor adjacent the web reel and the support drum. A moving mechanism moves and locates the nip safety guard and the finger presence sensor thereon depending on the size of the web reel so that the finger presence sensor is located closely spaced from the web reel and thus spaced a safe distance from the nip. The safety guard moving mechanism further is controlled by a controller which receives input from a web reel height measuring instrument, which allows proper positioning of the guard by the moving mechanism to position the finger sensor. More particularly, the winding machine nip safety guard comprises a safety shield that covers the support drum and is mounted for rotation about the support drum, the safety shield having an edge which can be moved to closely approach the web reel. The moving mechanism is used to move the safety shield away from the nip during higher speed winding and towards the nip before the operator approaches the winder.